Vibrational circular dichroism spectroscopy of chiral pheromones: frontalin (1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane)

Ab initio density functional theory (DFT) is used to predict the vibrational absorption and circular dichroism spectra of the insect pheromone 1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane: frontalin. Excellent agreement with experimental spectra is obtained for the structure in which the six-membered ring is in a chair conformation and the seven-membered ring is in a boat conformation. Vibrational circular dichroism (VCD) intensities, predicted on the basis of the previously determined absolute configuration, are in excellent agreement with experiment. We conclude that VCD spectroscopy, in combination with ab initio DFT, is now an efficient tool for determining the absolute configuration and/or conformation of chiral organic molecules, including pheromones. (C) 1998 Elsevier Science Ltd. All rights reserved.